Si-COAT 531AG Clear: Permanent Anti Graffiti Coating
Si-COAT 531AG Clear is a permanent anti graffiti coating made by CSL Silicones. Because it is clear, it goes over any colour, so painted trains, branded buildings and face brick keep their look. Once it cures, most graffiti washes off with a cold water pressure wash, without harsh solvents.
That breaks the usual cycle. Without protection, owners pay for chemical removal after every attack, and porous surfaces often keep a ghost of the tag. With a permanent coating, however, the protection stays in place after each clean.
How a Clear Anti Graffiti Coating Works
Many anti graffiti products are sacrificial. In other words, they wash off with the graffiti and must be reapplied after every clean. Si-COAT 531AG works differently. It is a permanent, non sacrificial polysiloxane coating that bonds chemically to the surface. Because the cured film is water repellent, paint sits on top of it rather than soaking in. As a result, the coating stays in place through repeated cleaning.
It goes on in a single coat, with no abrasive blasting. In most cases no primer is needed either, although CSL recommends a quick field adhesion test first.
Why Clear Makes Sense
A clear coating protects without changing the colour underneath. So you can coat almost anything, whatever its paint scheme or finish. For example, a rail operator can protect carriages in their livery, and a retailer can protect a branded shopfront without repainting it. Likewise, face brick, natural stone and murals keep their natural look. Also, there is no colour to match or order, which keeps specifications simple.
Where to Use Anti Graffiti Coating
CSL lists metal, concrete, brick, stone, wood, fibreglass and existing coatings as suitable surfaces. In practice, that covers most of what gets tagged. For municipalities, that means retaining walls, bridges, underpasses and public buildings. Rail operators can also coat train carriages, stations and boundary walls. In addition, commercial owners use it on facades, shopfronts, signage and perimeter walls. Utilities, too, can protect kiosks, substations and electrical boxes.
Bridges and underpasses often need corrosion work as well, as our article on bridge corrosion protection explains. For real projects, see our anti graffiti case studies.
Applying Si-COAT 531AG
- Surface: first remove dirt, dust, chalking paint, mortar spatter, loose rust, old caulking, grease, oil, curing compounds and laitance, so the surface is clean and dry.
- Adhesion: no primer is needed on most surfaces, but do a quick field adhesion test first.
- Mixing: stir with a powered mixer at 300 to 400 rpm for at least 5 minutes before use.
- Method: airless spray is recommended. Brush or roller suits small areas, although they need more than one coat.
- Thickness: about 0.15 to 0.25 mm once dry (6 to 10 mil, 152 to 254 µm). That works out to roughly 0.2 to 0.35 litres per m², before losses.
- Conditions: air and surface between 5°C and 60°C, and at least 3°C above the dew point. Otherwise, condensation can leave a matte finish.
- Cure at 25°C and 50% humidity: skin in 20 to 30 minutes, tack free in 60 to 90 minutes, cured through in 4 to 6 hours, full properties in 7 days.
Removing Graffiti From a Coated Surface
First, remove graffiti as soon as you can with a cold water pressure washer at about 1,200 psi. If paint has been left for more than 10 days and resists cold water, then switch to a warm water pressure wash. In rare cases, specialty paints with adhesion primers may still hold. For those, apply a biodegradable surfactant, such as dish soap, with a cleaning pad and rinse straight away. Always test any cleaner on a small, hidden patch first.
As a result, no solvents run off into stormwater drains. Once fully cured, the coating itself is also environmentally benign, according to CSL.
Anti Graffiti Coating FAQ
Can it go over painted surfaces?
Yes. CSL lists existing coatings as a suitable surface, as long as the paint is sound and clean. However, chalking or flaking paint must come off first.
How long does an anti graffiti coating last?
Si-COAT 531AG is permanent and non sacrificial, so cleaning does not remove it. It also stays stable from minus 60°C to 200°C. Still, after long weathering, clean the surface well before any overcoat.
Will the surface look different?
The original colour shows through, because the coating is clear. It does dry to a semi gloss sheen, though, so try a small test patch first, especially on matte surfaces such as face brick or stone.
Can building owners apply it themselves?
No. CSL intends it for professional applicators only. So TSS gives technical support and application guidance on every project.
Technical Solution Supplies distributes CSL Silicones products across Southern Africa, including the DRC and the Seychelles. For more answers, see the anti graffiti coating FAQ, our case studies, or contact us to discuss your site.
Proud exclusive distributor of CSL Silicones in Southern Africa.